The most familiar windmills are simply propeller blades mounted on a horizontal axis with a mechanism for keeping the blades turned into the wind. To utilize ordinary windmills for effective power generation, it has become apparent that the blades must be large, some having dimensions as large as 200 feet. These giant propellers have problems that seem to increase dramatically as the size increases--the longer they are, the more they tend to shake themselves to pieces. Even vertical axis windmills, like the Savonius rotor and the Darrieus turbine, may not be adaptable for large scale use. Severe aeroelastic problems are encountered in large scale devices. Because of these disadvantages inherent in common propeller blades, efforts have been made to augment the air flow through a windmill device in order to permit reduction in the blade size. An article describing various proposed designs for augmenter windmills is found on page 72 of the September 1978 edition of "Popular Science" magazine, published by Times Mirror Magazines, Inc.
It is the primary object of the present invention to provide a wind turbine which will get more air from the propeller than would be the case with ambient wind velocities.
Another object of the invention is to provide a vortex augmenter which will operate without the risk of additional static structures to create the vortex, such as an airfoil.
A further object of the invention is to provide a windmill which, by its inherent conception and design, will keep itself turned into the wind without the need for additional fins or other devices.
A still further object of the invention is to provide a power generating wind turbine whose blade size and total cost is substantially less than ordinary propeller bladed windmills with equivalent power generating capacity.
Other features and objects of the invention will become apparent from a reading of the following description of a preferred form of the invention taken in connection with the drawings.